html,
body {
    height: 100%;
}

body {
    margin: 0;
    padding: 8px;
    box-sizing: border-box;
}

#app {
    font-family: Avenir, Helvetica, Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-align: center;
    color: #2c3e50;
    height: 100%;
    display: flex;
    flex-direction: column;
}

#app > header {
    margin: 8px auto;
}

#app > section {
    flex: 1;
    overflow: hidden;
    position: relative;
    padding: 12px;
}

#app .canvas {
    width: 100%;
    height: 100%;
    display: block;
}

#app button {
    font-size: medium;
}
